What do you prefer? ...

This is for a melee character.

Merc wields reapers toll, shael'd.
Armor choices: eth treachery, eFort
helm: guillaume (a must imo) with a nice ias/ehnDam jewel, or another guillaume with cham.

No teleport on the character.
Note that the fastest breakpoint for the merc is 9 fpa, wich im not aiming for.

1) I could get 10 fpa with treachery and any guillaume (cham or ias/ed ?)
2) 11 fpa with fort and ias guillaume
3) 12 fpa with fort and guillaume cham'd

Eth reaper Eth treachery and Guilli was allways best combo
for Act2 merc

But it really dosent matter of you give him eth forti or eth treachery he really cannot die with you playing your character with him? xd

Mercenary was allways just +Bonus to your character,
and as you are melee physisal attacker? Than its enough that he is using Reapers toll

Decrepify on enemies generally removes physical immunities and causes monsters to take extra physical damage and thats all what matters to you its ++bonus to your character to clear all fast